This invention relates to a process for producing an aromatic carbonate compound. More specifically, it relates to production of an easily purifiable aromatic carbonate compound in a high yield and a high selectivity by reacting a phenolic compound with a di-aliphatic carbonate or an aliphatic-aromatic carbonate in the presence of a specific catalyst.
(2) Description of the Prior Art
It is well known to produce an aliphatic-aromatic carbonate, a di-aromatic carbonate or an aromatic carbonate composed of a mixture of both by reacting a phenolic compound with a di-aliphatic carbonate or an aliphatic-aromatic carbonate. This reaction is shown by the following reaction equations. ##STR2##
In the reactions (1) and (2), the equilibrium constants K.sub.1 and K.sub.2 shown below are low, the equilibrium is shifted to the starting material side, and the reaction rate is slow. Hence, the yields of ROCO.sub.2 Ar and ArOCO.sub.2 Ar are very low. ##EQU1##
Accordingly, many attempts have been made to select suitable catalysts for increasing the yield of the product in this reaction system.
For example, Japanese Laid-Open Patent Publication No. 105032/1976 discloses Lewis acids, metal compounds and transition metal compounds capable of forming Lewis acids, and cites SnX.sub.4 (X is halogen, acetoxy, alkoxy or aryloxy) as preferred examples.
Japanese Laid-Open Patent Publication No. 48733/1979 discloses an organotin catalyst represented by the following formula EQU (R.sup.1).sub.4-x --SnO(Y).sub.x
wherein Y represents the OCOR.sup.2 group, OH group or OR.sup.2 group, R.sup.1 and R.sup.2 are identical or different and each represents an alkyl group having 1 to 12carbon atoms, an aryl group having 6 to 12 carbon atoms. or an alkylaryl group having 7 to 12 carbon atoms, and x is an integer of 1 to 3,
which has no tin-halogen bond.
Japanese Laid-Open Patent Publication No. 63023/1979 discloses a tin alkoxide represented by the following formula EQU R.sub.3-l Sn(OR.sup.1).sub.1+l
wherein R and R.sup.1 represent a hydrocarbon group and l is an integer of 0 to 2.
Japanese Laid-Open Patent Publication No. 169444/1985 discloses a polymeric tin compound represented by the following formula ##STR3## wherein R and R.sup.1 represent a hydrocarbon group.
Japanese Laid-Open Patent Publication No. 169445/1985 discloses a tin compound of the following formula ##STR4## wherein R represents a hydrocarbon group or a hydrocarbon-oxy group.
Japanese Laid-Open Patent Publication No. 277345/1987 states that a tin compound represented by the following formula ##STR5## wherein R represents and alkyl group having 1 to 12 carbon atoms can be used as a reaction catalyst for the production of aromatic carbonates.
These previously known tin-containing catalysts increase the yields of the products in the reaction systems to some extent, but still have insufficient catalytic activity. Accordingly, this makes it difficult to purify the products.
Japanese Laid-Open Patent Publication No. 105032/1976 cited above also describes AlX.sub.3, TiX.sub.3, TiX.sub.4, UX.sub.4, VOX.sub.3, VX.sub.5, ZnX.sub.2, and FeX.sub.3 (where X is halogen, acetoxy, alkoxy or aryloxy) as preferred examples of the Lewis acids and metal compounds and transition metal compounds capable of forming Lewis acids. However, the Lewis acids are corrosive and are not desirable for the reaction apparatus and the like. The method involving the use of the above compounds is low in the yield of the desired product, and cannot be said to be commercially advantageous.